First, here's what happened: I had OS X Mavericks (10.9) installed on my MacBook Pro. Then I wiped the operating system to get Windows 7 instead. After that, I went to install Ubuntu 12.04, but while installing, it wiped Windows 7 as well. Now I'm looking to reinstall Mac OS X, but I can't edit the partitions to create unallocated space, because it is stored in the ext4 partiton, mounted at "/". Any help would be appreciated.
edit: when I try to boot from any device (disk/USB/SD) this message shows up twice [error: efidisk read error.]